Programming Questions 1. Array Manipulation: Move all zeros to the end of a given array. Solve the problem of buying and selling a product to maximize profit, given its prices on different days from a given price array. Find the 3rd highest element in an array. Find the 2nd duplicate number in an array. 2. String Manipulation: Given a string s, find the length of the longest substring without repeating characters. (Example: s = "abcabcbb") Find the first repeating number in an array. (Example: arr[] = {10, 5, 3, 4, 5, 3, 6}) Given a List<string>: var list = new List<string> {"Ravi Kumar", "Neha Gupta", "Arti Gupta", "Kamal Rai"}; get the count of the surnames and maintain the order. 3. C# Code Execution: Determine the order of printing in a C# class with static constructors, instance constructors, and regular constructors. General Problem-Solving: Dry run a piece of code and optimize its complexity. C# Core Concepts 1. LINQ (Language Integrated Query): Steps for initializing LINQ queries. How intermediate operations work in LINQ (e.g., Where, Select). How terminal operations work in LINQ (e.g., ToList(), FirstOrDefault()). What is a parallel LINQ (PLINQ) query? 2. Collections Framework: Difference between IComparable and IComparer. How Dictionary<TKey, TValue> works in C#. Difference between ICollection and IEnumerable. Overview of the Collection framework starting from the base interface IEnumerable and its methods. 3. Exception Handling: How to create custom exceptions in C#. Difference between Thread.Sleep() and Task.Delay() methods. 4. Polymorphism and OOP Concepts: Method overloading and method overriding. Difference between == and .Equals() in string comparison. Multithreading and the use of lock statements. Understanding marker interfaces, functional interfaces (like delegates), and design patterns such as Singleton and Factory. SOLID principles. 5. ASP.NET Core: Difference between ASP.NET Core MVC and Web API, and which is better and why. ASP.NET Core inbuilt server (Kestrel). Difference between Razor Pages and MVC. Understanding JWT tokens and how they secure applications using HTTPS. 6. Miscellaneous C#: Understanding the order of execution in blocks (static constructor, instance constructor, regular constructor). Questions related to classes and methods, such as Animal and Cat with overridden methods. SQL: 1. Complex Queries: Find the third-highest salary in SQL. Understanding the order of execution in SQL queries (e.g., Empid, dept, manager id). 2. Data Structures and Algorithms (DSA): Array and String Problems:
...